1. Field of the Invention
The present invention relates to a rear window glass antenna for use on an automobile for receiving radio or television broadcast signals.
2. Description of the Prior Art
It is customary for automobiles to have an antenna on a rear window glass panel for receiving radio or television broadcast signals in combination with a plurality of defrosting electric wires. The rear window glass antenna has antenna wires including a folded portion to achieve phase adjustment with respect to certain frequency bands for an increased reception gain.
Any portions of the antenna wires which are exposed cut of a masked area on the rear window glass would pose a problem on the appearance of the rear window glass. Therefore, the width of the folded portion of the antenna wires which is exposed out of the masked region should not be too large, and is usually held to 1 mm.
The antenna wires in the masked area where they are concealed by a flange of the automobile body have a width ranging from 3 to 5 mm.
Since the folded portion of the antenna wires has a high impedance, its sensitivity is very low because of the small width of about 1 mm.
One known rear window glass antenna is disclosed in Japanese patent publication No. 61-5282 published Feb. 17, 1986.